Semiconductor structure with integrated passive structures

ABSTRACT

A metal-oxide-semiconductor field-effect transistor (MOSFET) with integrated passive structures and methods of manufacturing the same is disclosed. The method includes forming a stacked structure in an active region and at least one shallow trench isolation (STI) structure adjacent to the stacked structure. The method further includes forming a semiconductor layer directly in contact with the at least one STI structure and the stacked structure. The method further includes patterning the semiconductor layer and the stacked structure to form an active device in the active region and a passive structure of the semiconductor layer directly on the at least one STI structure.

FIELD OF THE INVENTION

The invention relates to semiconductor structures and, moreparticularly, to a metal-oxide-semiconductor field-effect transistor(MOSFET) with integrated passive structures and methods of manufacturingthe same.

BACKGROUND

Semiconductor fabrication processes and resulting semiconductor deviceshave significantly advanced over the years, creating higher performingdevices with higher density and lower cost. These developments includegeometric scaling of the semiconductor devices, which is made possibleby many processes and material advances in the semiconductor industry.These advances allow fabrication of transistors such as, for example,complementary metal oxide semiconductors (CMOS) and bipolar junctiontransistors (BJT).

CMOS processes can be used to fabricate microprocessors,microcontrollers, static RAM, and other digital logic circuits. CMOSfabrication processes include the deposition and patterning of manylayers, under certain conditions and process flows. For example, MOSFETdevices can be formed with high-k-dielectric materials with metal gates,by deposition, lithography and etching processes.

SUMMARY

In one or more embodiments of the invention a method comprises forming astacked structure in an active region and at least one shallow trenchisolation (STI) structure adjacent to the stacked structure. The methodfurther comprises forming a semiconductor layer directly in contact withthe at least one STI structure and the stacked structure. The methodfurther comprises patterning the semiconductor layer and the stackedstructure to form an active device in the active region and a passivestructure of the semiconductor layer directly on the at least one STIstructure.

In one or more embodiments of the invention, a method comprises forminga layered structure comprising: forming a high-k dielectric material ona substrate; forming a metal material on the high-k dielectric material;forming a semiconductor material over the metal material; and forming amasking layer over the semiconductor material. The method furthercomprises patterning the layered structure to form a stacked structurein an active region. The method further comprises forming shallow trenchisolation (STI) structures adjacent to the stacked structure in theactive region. The method further comprises removing the masking layer,after the formation of the STI structures. The method further comprisesforming a semiconductor layer directly on the STI structures and thesemiconductor material of the stacked structure. The method furthercomprises forming at least one passive structure by patterning of thesemiconductor layer. The method further comprises forming an activedevice by the patterning of the semiconductor layer and the stackedstructure.

In one or more embodiments of the invention, a structure comprises anactive device comprising: a high-k dielectric material on a substrate; ametal material on the high-k dielectric material; and a semiconductormaterial over the metal material. The structure further comprises apassive structure comprising semiconductor directly in contact withshallow trench isolation structures, adjacent to the active device. Thestructure further comprises an insulating layer formed between and overthe active device and passive structure, wherein the insulating layer isdevoid of keyholes. The active device is formed with a height greaterthan the passive structure.

In another aspect of the invention, a design structure tangibly embodiedin a machine readable storage medium for designing, manufacturing, ortesting an integrated circuit is provided. The design structurecomprises the structures of the present invention. In furtherembodiments, a hardware description language (HDL) design structureencoded on a machine-readable data storage medium comprises elementsthat when processed in a computer-aided design system generates amachine-executable representation of the semiconductor structure, whichcomprises the structures of the present invention. In still furtherembodiments, a method in a computer-aided design system is provided forgenerating a functional design model of the semiconductor structure. Themethod comprises generating a functional representation of thestructural elements of the semiconductor structure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention is described in the detailed description whichfollows, in reference to the noted plurality of drawings by way ofnon-limiting examples of exemplary embodiments of the present invention.

FIGS. 1-7 and 9-11 show processing steps and respective structures inaccordance with aspects of the present invention;

FIGS. 8 a and 8 b show alternative intermediate structures andrespective processing steps in accordance with aspects of the presentinvention;

FIG. 12 shows a comparison graph of devices manufactured in accordancewith the present invention vs. a conventional structure; and

FIG. 13 is a flow diagram of a design process used in semiconductordesign, manufacture, and/or test.

DETAILED DESCRIPTION

The invention relates to semiconductor structures and, moreparticularly, to a metal-oxide-semiconductor field-effect transistor(MOSFET) with integrated passive structures and methods of manufacturingthe same. Advantageously, the methods of manufacturing the MOSFET resultin a reduction or total elimination of STI (shallow trench isolation)divots, while enabling integration of polysilicon (or othersemiconductor material) passive structures (e.g., resistors, efuses,etc.) in high-k dielectric and metal gate flows. Also, in embodiments,the methods of the present invention reduce fabrication processes, byeliminating masking steps which, in turn, reduces overall fabricationtime and costs and improves yield of the manufacturing process.

FIG. 1 shows a beginning structure in accordance with aspects of thepresent invention. It should be understood by those of skill in the artthat the present invention can be implemented using any conventionalsilicon-on-insulator (SOI) or bulk silicon technologies, fabricatedusing known processes, e.g., SiMOX for SOI or other bondingtechnologies. For purposes of this discussion, the process flows andrespective structures of the present invention will be described withregard to an SOI implementation, however, where appropriate, thedescription will discuss bulk silicon processes.

In FIG. 1, the beginning structure 5 includes a buried oxide layer 10.The buried oxide layer 10 can be formed on any known substrate. Asilicon-on-insulator layer 12 is formed on the buried oxide layer 10. Inembodiments, the layer 12 can be bonded or formed in any conventionalmanner on the buried oxide layer 10, as should be understood by those ofskill in the art. The layer 12 can be, for example, Si, SiGe, SiC or Ge,GeAs or other known semiconductor materials. A high-k dielectricmaterial 14 is formed on the layer 12. In embodiments, the high-kdielectric material 14 can be, for example, hafnium, hafnium oxide,hafnium dioxide, etc. The high-k dielectric material 14 can be formed bya deposition process, e.g., atomic layer deposition (ALD) or chemicalvapor deposition (CVD), to a thickness ranging from about 1 nm to about200 nm. In embodiments, an interface layer such as an oxide oroxynitride or nitride can be placed between layer 12 and layer 14 (whichcan also be represented as reference numeral 14).

Still referring to FIG. 1, a metal gate material 16 is formed on thehigh-k material 14. In embodiments, the metal gate material 16 can beTiN, TaN, Al, or W as examples. The metal gate material 16 can bedeposited using a metal sputtering process, CVD, ALD, or a physicalvapor deposition process, known to those of skill in the art. Inembodiments, the metal gate material 16 can be deposited to a thicknessranging from about 1 nm to about 200 nm. A semiconductor material 18,e.g., silicon based material, is formed on the metal gate material 16.The semiconductor material 18 can be deposited using a conventional CVDsuch as, for example, low pressure CVD (LPCVD) or rapid thermal CVD(RTCVD). This semiconductor material 18 can be polysilicon or amorphoussilicon, and is preferably 5 nm to 200 nm in thickness. In addition tosilicon, the semiconductor material 18 can be any semiconductor materialsuch as Ge, SiGe, or SiC. A hardmask 20 is deposited on thesemiconductor material 18. The hardmask 20 can be a silicon nitridematerial, for example.

In FIG. 2, the layer 12, high-k material 14, metal gate material 16, thesemiconductor material 18 and hardmask 20 can be patterned to form astacked structure in an active region 22. The patterning can beperformed using conventional lithography and etching processes. Forexample, a photoresist mask can be formed over the hardmask 20 andexposed to energy (light) to form a pattern (opening). A reactive ionetching (RIE) can then be performed to pattern the layers 12, 14, 16, 18and 20 into a stacked structure in the active region 22. The etchingwill stop on the buried oxide layer 10. In the bulk implementation, theetching can continue into the bulk layer to about 200 nm+/−100 nm, inorder to define the stacked structure in the active region 22.

As should be understood by those of skill in the art, two or more RIEchemistries can be used to pattern the different materials of layers 12,14, 16, 18 and 20. For example, a first RIE chemistry can be used toremove layers 18 and 20; whereas, additional RIE chemistries can be usedto selective remove layers 12, 14 and 16. Any residual resist can beremoved using conventional resist strip processes.

In FIG. 3, a liner 24 is formed over the top and side surfaces of thestacked structure in the active region 22, and exposed surfaces of theburied oxide layer 10. In the bulk implementation, the liner 24 would beformed over the exposed surfaces of silicon (bulk), which can also beschematically represented by the structure of FIG. 3. The liner 24 canbe a silicon nitride or silicon oxynitride liner formed to a thicknessof about 10 Å to 200 Å; although, other dimensions are also contemplatedby the present invention. The liner 24 can be formed using aconventionally known CVD process. In embodiments, the liner 24 willprovide protection to the high-k dielectric material 14, duringsubsequent processes. The liner 24 will also act as an encapsulationduring subsequent STI formation processes.

Still referring to FIG. 3, an insulator layer 26 is formed over theliner 24. In embodiments, the insulator layer 26 can be, for example,silicon dioxide (SiO₂), deposited using a CVD process. In embodiments,as described further herein, the SiO₂ will be used to form recessed STIstructures, on sides of the active region 22.

As shown in FIG. 4, the insulator layer 26 is planarized to form regions26 a, separated by the stacked structure formed in the active region 22.For example, in embodiments, the insulator layer 26 can undergo achemical mechanical polishing (CMP) process, which will stop on eitherlayer 20 or liner 24 (as such layers, in embodiments, may be made of thesame material). This CMP process results in insulator regions 26 a.

In FIG. 5, the insulator regions 26 a (shown in FIG. 4) are recessed by,for example, a selective etching process which forms STI structures 26b. For example, in embodiments, the insulator regions can be recessed bya dilute hydrofluoric acid (DHF) oxide etch, to form STI structures 26 bon the sides of the stacked structure in the active region 22. As shouldbe understood by those of skill in the art, the use of DHF does notrequire the use of an additional masking processes. In embodiments, theSTI structures 26 b are aligned with the semiconductor material 18 ofthe stacked structure; that is, the top surface of the STI structures 26b is planar or substantially planar with a top surface of thesemiconductor material 18.

In FIG. 6, the silicon nitride layer (layer 20 shown in FIG. 5) isremoved by an etch process such as RIE or aqueous chemical etch. In thisway, the structure of FIG. 6 has a planar surface comprising the STIstructures 26 b and the semiconductor material 18. The nitride liner 24will protect the high-k dielectric material 14 from attack during theRIE process. In embodiments, the structure of FIG. 6 can undergo acleaning process in order to ensure that oxide does not form on thesemiconductor material 18.

FIG. 7 shows the formation of a semiconductor material 28 over the STIstructures 26 b and the semiconductor material 18 of the stackedstructure in the active region 22. More specifically, the semiconductormaterial 28 is formed directly in contact with the STI structures 26 b(e.g., directly in contact with oxide material) and the semiconductormaterial 18. Due to the planar structure shown in FIG. 6, the depositionprocess of the semiconductor material 28 should also result in asubstantially planar surface. In embodiments, the semiconductor material28 can be formed by a CVD such as LPCVD or RTCVD, for example. Thesemiconductor material 28 can be formed to a thickness of about 5 nm toabout 200 nm; although other dimensions are contemplated by the presentinvention. The semiconductor material 28 can be an amorphous orpolysilicon layer, any semiconductor material, including Ge or compoundsemiconductors such as SiGe, or other materials described herein withregard to the semiconductor material 18.

FIGS. 8 a and 8 b show alternative structures and fabrication processesin accordance with aspects of the present invention. More specifically,FIGS. 8 a and 8 b show the STI structure 26 b being non-planar (notflush) over the stacked structure in the active region 22. For example,in FIG. 8 a, an underfill of region 26 b results in protrusion 28 a ofthe semiconductor material 28 over the stacked structure in the activeregion 22; whereas, in FIG. 8 b, an overfill of region 26 b results in aslight recess 28 b of the semiconductor material 28 over the stackedstructure in the active region 22. In embodiments, the underfill andoverfill can be intentionally used, in order to optimize (e.g., tune)the thickness of the silicon layer 28. In either case, the topography ofthe structures shown in FIGS. 8 a and/or 8 b can be planarized to formthe structure shown in FIG. 7, such that the top surface of thesemiconductor material 28 is substantially planar.

In FIG. 9, well implantation processes are optionally performed throughthe semiconductor material 28, as represented by the arrows. Morespecifically, the well implantation process can be, for example, aphosphorous or arsenic implant process for a PFET device, and a boronimplant process for a NFET device, but are not restricted to thesedopant types or species. In embodiments, the energy and concentrationlevels of the implant process are sufficient to reach into thesemiconductor layer, e.g., layer 12. As should be understood by those ofskill in the art, the energy and concentration levels of the implantprocess can vary, depending on the thickness of the underlying materialsand desired device properties.

By way of example, in order to implant through a combined thickness of50-100 nm for layers 28, 18, 16 and 14 into layer 12, the energy ofimplantation species such as boron, BF₂, arsenic, or phosphorus can be10 KeV to 200 KeV at an areal concentration of 1E12 cm⁻² to 1E14 cm⁻².The implants can be masked for each FET type and tuning, as should beunderstood by those skilled in the art. Advantageously, if the implantprocess is performed after the deposition of the semiconductor material28, there is no change in gate topography due to subsequent cleans andresist stripping processes. An optional anneal process can also beperformed to diffuse, activate and stabilize the dopants, after theimplanting process.

FIG. 10 shows a cross sectional view of the structure, perpendicular toan active device, e.g., transistor, and respective processing steps inaccordance with aspects of the present invention. More specifically, inFIG. 10, an etching process is performed to form passive structures 30 a(on the STI structures 26 b) and an active device 30 b, e.g., transistorin the active region. The etching of the semiconductor material 28 toform the active device 30 b and the passive structures 30 a can beperformed in a single patterning step, thus reducing masking steps. Theetching process can be, for example, a conventional RIE processperformed through the layers 14, 16, 18 and 28 to form the transistor 30b (e.g., MOSFET), and through layer 28 to form the passive structures 30a, over the STI structures 26 b. The passive structures 30 a can be, forexample, an e-fuse or a resistor, and advantageously, will not have anyunderlying dielectric material (as in conventional structures).

As further shown in FIG. 10, the passive structures 30 a only comprisethe semiconductor material 28, directly contacting the STI structures 26b; that is, there are no intervening layers, e.g., high-k dielectricand/or metal material, between the semiconductor material 28 of thepassive structures 30 a and the oxide of the STI structures 26 b.Advantageously, this configuration will reduce processing steps byeliminating a masking step that would otherwise be needed to remove theintervening materials in conventional methods and structures. Also,advantageously, this structure will (i) increase the resistance of theresistor by eliminating any metal material under the resistor, (ii)allow the resistance of the silicon resistor to be tuned by adjustingdopant concentrations, or (iii) eliminate unwanted electrical shorts ofan e-fuse structure, even after the e-fuse is blown (which wouldotherwise result when metal material remains intact under the e-fuse).

Still referring to FIG. 10, the passive structures 30 a and thetransistor 30 b are formed at different heights (due to the height ofthe STI structures 26 b), e.g., the passive structures 30 a are formedwith a height of “X” and the transistor gate 30 b is formed with aheight of “Y”, where Y>X. As an example, the height “X” of the passivestructures 30 a can be about 200 Å or more. As discussed in more detailwith reference to FIG. 11, this aspect ratio will avoid insulatorvoid-fill issues.

As further shown in FIG. 10, the top surface of the passive structures30 a and the transistor gate 30 b are substantially coplanar. Thisuniformly level top surface of the passive devices 30 a and transistorgates 30 b make gate patterning lithography more straightforward toperform and subsequent depositions easier to fill uniformly, compared toconventional structures and methods which may result in the top surfaceof the passive device and transistor gate varying in height.

As shown in FIG. 11, an insulating layer 32 is formed over and betweenthe passive structures 30 a and the transistor 30 b. In embodiments, theinsulating layer 32 can be formed by conventional deposition processes,e.g., CVD. The insulating layer 32 can be a compressive stress liner ora tensile stress liner or a neutral stress film, depending on the typeof transistor. For example, a compressive stress liner can be used for aPFET type device; whereas, a tensile stress liner can be used for a NFETtype device. As an example, the insulating layer 32 can be siliconnitride or oxide or a combination thereof. It should be understood bythose skilled in the art that there are additional fabrication steps areprovided between patterning of the gates 30 a and passive devices 30 bshown in FIG. 10, and the deposition of the insulating layers shown inFIG. 11. These intervening process steps can include spacer formations,implants, source/drain formations and silicide formation, all known tothose of skill in the art.

Advantageously, as the height “X” of passive structure 30 a is shorterthan the height “Y” of the transistor 30 b, it is now possible to formthe insulating layer 32 without any keyholes (e.g., void-fill issues).As should be understood by those of skill in the art, the presence ofkeyholes lead to undesired tungsten in the insulating layer causingshorts, however, for the shorter height of the passive structures 30 a,the aspect ratio is reduced and easier to fill.

FIG. 12 shows a comparison graph of structures manufactured inaccordance with the present invention vs. a conventional structure. InFIG. 12, the Y axis is a measurement of drain current in log scale, andthe X axis shows gate voltage. As shown, line “B” is representative ofthe structure of the present invention having ideal characteristics;whereas line “A” is representative of a conventional structure having akink due to corner device effect. As should be understood by those ofordinary skill in the art, the structure of the present inventionexhibits ideal characteristics, i.e., higher threshold voltage comparedto the conventional structure, due to the fabrication processes andstructure that reduce or eliminate STI divots.

FIG. 13 is a flow diagram of a design process used in semiconductordesign, manufacture, and/or test. FIG. 13 shows a block diagram of anexemplary design flow 900 used for example, in semiconductor IC logicdesign, simulation, test, layout, and manufacture. Design flow 900includes processes, machines and/or mechanisms for processing designstructures or devices to generate logically or otherwise functionallyequivalent representations of the design structures and/or devicesdescribed above and shown in FIGS. 1-11. The design structures processedand/or generated by design flow 900 may be encoded on machine-readabletransmission or storage media to include data and/or instructions thatwhen executed or otherwise processed on a data processing systemgenerate a logically, structurally, mechanically, or otherwisefunctionally equivalent representation of hardware components, circuits,devices, or systems. Machines include, but are not limited to, anymachine used in an IC design process, such as designing, manufacturing,or simulating a circuit, component, device, or system. For example,machines may include: lithography machines, machines and/or equipmentfor generating masks (e.g. e-beam writers), computers or equipment forsimulating design structures, any apparatus used in the manufacturing ortest process, or any machines for programming functionally equivalentrepresentations of the design structures into any medium (e.g. a machinefor programming a programmable gate array).

Design flow 900 may vary depending on the type of representation beingdesigned. For example, a design flow 900 for building an applicationspecific IC (ASIC) may differ from a design flow 900 for designing astandard component or from a design flow 900 for instantiating thedesign into a programmable array, for example a programmable gate array(PGA) or a field programmable gate array (FPGA) offered by Altera® Inc.or Xilinx® Inc.

FIG. 13 illustrates multiple such design structures including an inputdesign structure 920 that is preferably processed by a design process910. Design structure 920 may be a logical simulation design structuregenerated and processed by design process 910 to produce a logicallyequivalent functional representation of a hardware device. Designstructure 920 may also or alternatively comprise data and/or programinstructions that when processed by design process 910, generate afunctional representation of the physical structure of a hardwaredevice. Whether representing functional and/or structural designfeatures, design structure 920 may be generated using electroniccomputer-aided design (ECAD) such as implemented by a coredeveloper/designer. When encoded on a machine-readable datatransmission, gate array, or storage medium, design structure 920 may beaccessed and processed by one or more hardware and/or software moduleswithin design process 910 to simulate or otherwise functionallyrepresent an electronic component, circuit, electronic or logic module,apparatus, device, or system such as those shown in FIGS. 1-11. As such,design structure 920 may comprise files or other data structuresincluding human and/or machine-readable source code, compiledstructures, and computer-executable code structures that when processedby a design or simulation data processing system, functionally simulateor otherwise represent circuits or other levels of hardware logicdesign. Such data structures may include hardware-description language(HDL) design entities or other data structures conforming to and/orcompatible with lower-level HDL design languages such as Verilog andVHDL, and/or higher level design languages such as C or C++.

Design process 910 preferably employs and incorporates hardware and/orsoftware modules for synthesizing, translating, or otherwise processinga design/simulation functional equivalent of the components, circuits,devices, or logic structures shown in FIGS. 1-11 to generate a netlist980 which may contain design structures such as design structure 920.Netlist 980 may comprise, for example, compiled or otherwise processeddata structures representing a list of wires, discrete components, logicgates, control circuits, I/O devices, models, etc. that describes theconnections to other elements and circuits in an integrated circuitdesign. Netlist 980 may be synthesized using an iterative process inwhich netlist 980 is resynthesized one or more times depending on designspecifications and parameters for the device. As with other designstructure types described herein, netlist 980 may be recorded on amachine-readable data storage medium or programmed into a programmablegate array. The medium may be a non-volatile storage medium such as amagnetic or optical disk drive, a programmable gate array, a compactflash, or other flash memory. Additionally, or in the alternative, themedium may be a system or cache memory, buffer space, or electrically oroptically conductive devices and materials on which data packets may betransmitted and intermediately stored via the Internet, or othernetworking suitable means.

Design process 910 may include hardware and software modules forprocessing a variety of input data structure types including netlist980. Such data structure types may reside, for example, within libraryelements 930 and include a set of commonly used elements, circuits, anddevices, including models, layouts, and symbolic representations, for agiven manufacturing technology (e.g., different technology nodes, 32 nm,45 nm, 90 nm, etc.). The data structure types may further include designspecifications 940, characterization data 950, verification data 960,design rules 970, and test data files 985 which may include input testpatterns, output test results, and other testing information. Designprocess 910 may further include, for example, standard mechanical designprocesses such as stress analysis, thermal analysis, mechanical eventsimulation, process simulation for operations such as casting, molding,and die press forming, etc. One of ordinary skill in the art ofmechanical design can appreciate the extent of possible mechanicaldesign tools and applications used in design process 910 withoutdeviating from the scope and spirit of the invention. Design process 910may also include modules for performing standard circuit designprocesses such as timing analysis, verification, design rule checking,place and route operations, etc.

Design process 910 employs and incorporates logic and physical designtools such as HDL compilers and simulation model build tools to processdesign structure 920 together with some or all of the depictedsupporting data structures along with any additional mechanical designor data (if applicable), to generate a second design structure 990.

Design structure 990 resides on a storage medium or programmable gatearray in a data format used for the exchange of data of mechanicaldevices and structures (e.g. information stored in a IGES, DXF,Parasolid XT, JT, DRG, or any other suitable format for storing orrendering such mechanical design structures). Similar to designstructure 920, design structure 990 preferably comprises one or morefiles, data structures, or other computer-encoded data or instructionsthat reside on transmission or data storage media and that whenprocessed by an ECAD system generate a logically or otherwisefunctionally equivalent form of one or more of the embodiments of theinvention shown in FIGS. 1-11. In one embodiment, design structure 990may comprise a compiled, executable HDL simulation model thatfunctionally simulates the devices shown in FIGS. 1-11.

Design structure 990 may also employ a data format used for the exchangeof layout data of integrated circuits and/or symbolic data format (e.g.information stored in a GDSII (GDS2), GL1, OASIS, map files, or anyother suitable format for storing such design data structures). Designstructure 990 may comprise information such as, for example, symbolicdata, map files, test data files, design content files, manufacturingdata, layout parameters, wires, levels of metal, vias, shapes, data forrouting through the manufacturing line, and any other data required by amanufacturer or other designer/developer to produce a device orstructure as described above and shown in FIGS. 1-11. Design structure990 may then proceed to a stage 995 where, for example, design structure990: proceeds to tape-out, is released to manufacturing, is released toa mask house, is sent to another design house, is sent back to thecustomer, etc.

The method as described above is used in the fabrication of integratedcircuit chips. The resulting integrated circuit chips can be distributedby the fabricator in raw wafer form (that is, as a single wafer that hasmultiple unpackaged chips), as a bare die, or in a packaged form. In thelatter case the chip is mounted in a single chip package (such as aplastic carrier, with leads that are affixed to a motherboard or otherhigher level carrier) or in a multichip package (such as a ceramiccarrier that has either or both surface interconnections or buriedinterconnections). In any case the chip is then integrated with otherchips, discrete circuit elements, and/or other signal processing devicesas part of either (a) an intermediate product, such as a motherboard, or(b) an end product. The end product can be any product that includesintegrated circuit chips, ranging from toys and other low-endapplications to advanced computer products having a display, a keyboardor other input device, and a central processor.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed:
 1. A method comprising: forming a stacked structure inan active region; forming at least one shallow trench isolation (STI)structure adjacent to the stacked structure; forming a semiconductorlayer directly in contact with the at least one STI structure and thestacked structure; patterning the semiconductor layer and the stackedstructure to form an active device in the active region and a passivestructure of the semiconductor layer directly on the at least one STIstructure; and ion implanting dopant impurities to penetrate the stackedstructure and into a substrate to form wells in the substrate of theactive region after the forming of the semiconductor layer and prior tothe patterning the semiconductor layer and the stacked structure.
 2. Themethod of claim 1, wherein the stacked structure comprises a high-kdielectric material formed on a substrate, a metal material formed onthe high-k dielectric material and a semiconductor material formed overthe metal material, and the at least one STI structure is an insulatormaterial.
 3. The method of claim 2, further comprising recessing the atleast one STI structure to be planar with the semiconductor materialformed on the metal material of the stacked structure.
 4. The method ofclaim 2, wherein the stacked structure further comprising a nitridematerial over the semiconductor material, wherein the nitride materialis removed prior to the forming of the semiconductor layer.
 5. Themethod of claim 1, wherein the semiconductor layer is a polycrystallinesilicon or amorphous silicon.
 6. The method of claim 1, wherein thestacked structured is patterned prior to the formation of the at leastone STI structure and the semiconductor layer.
 7. The method of claim 1,further comprising forming a liner on the stacked structure, prior tothe forming of the at least one STI structure and wherein the liner isformed on a top surface and one or more side surfaces of the stackedstructure.
 8. The method of claim 1, wherein the active device has aheight greater than the passive structure of the semiconductor layer anda top surface of the active device and a top surface of the passivestructure are coplanar.
 9. The method of claim 8, further comprisingforming an insulating layer over and between the active device and thepassive structure, wherein the forming of the insulating layer is devoidof keyholes due to an aspect ratio between the passive structure and theactive device.
 10. The method of claim 1, wherein the semiconductorlayer thickness is tuned prior to the patterning step.
 11. The method ofclaim 1, wherein the patterning of the semiconductor layer to form theactive device and the passive structure is provided in a singlepatterning step.
 12. The method of claim 1, further comprising forming aliner directly on the stacked structure and over a substrate, whereinthe at least one shallow trench isolation (STI) structure is provideddirectly on the liner and forming a stacked structure in the activeregion includes an etching that continues into a buried oxide layer. 13.The method of claim 12, wherein the at least one shallow trenchisolation (STI) structure is formed to surround sidewalls of the stackedstructure.